I've got a 2009 MacBook Pro running OS X 10.5.7 and a Synology Diskstation ds215j. I've successfully set up a user for Time Machine on the NAS and have successfully performed backups.
However, this only works over wifi! When I connect [my Mac] to my router via Ethernet cable, Time Machine fails to find the disk. Both DHCP addresses (wired and wireless) are on the same subnet, which is the same subnet as the NAS.
Can anybody tell me why?!